Prior devices are used for the purpose of introducing holes, boreholes, for example, into a workpiece with the aid of a laser beam. For this purpose, the laser beam is directed toward the workpiece surface. In this case, the material of the workpiece is locally heated, melted, and partially vaporized by the high intensity of the laser beam. The molten metal is driven out of the borehole produced by the relatively high vapor pressure. Due to the high kinetic energy of the molten metal, molten metal droplets separate at the edge of the hole. These cool down in the medium surrounding the borehole, such as the surrounding air, and partially accumulate together with the condensed vapor on the workpiece surface. As a function of the kinetic energy of these particles, their temperature, and the medium surrounding the borehole, a coating made of ablation products, some of which adheres firmly, results on the workpiece surface, which is not desirable. The particle deposition may make complex and costly reprocessing of the workpiece necessary.
If a conventional protective gas nozzle is used, whose gas flow runs coaxially to the laser beam to protect the optical device from the molten particles rising from the hole edge and the condensed metal vapor, the molten particles are deflected by this gas beam, which is directed perpendicularly toward the workpiece surface, and pressed back onto the workpiece surface, which favors the undesired adhesion of the particles on the workpiece surface.